Organic and metallic precursors have been used in recent years to prepare advanced coating materials such as titanium nitride, vanadium nitride, boron nitride, tungsten dinitride, etc. These advanced coating materials have advantageously been deposited onto transparent glazings, e.g., glass, by well-known coating processes such as, for example, atmospheric pressure chemical vapor deposition (APCVD), low pressure chemical vapor deposition (LPCVD), spray pyrolysis, plasma enhanced chemical vapor deposition (PECVD), laser-induced chemical vapor deposition (LCVD), etc. The ultimately produced coated glazings may be used in automotive or architectural applications which require reduced solar and infrared radiation transmittances.
Titanium nitride is a particularly useful advanced material having several desirable properties such as, for example, high hardness (8-9 on the Moh scale), excellent solar and infrared reflectances, and nonreactivity with a variety of corrosive atmosphere.
Titanium nitride films may be deposited onto glass by continuously coating a hot glass ribbon as it is being produced by the well-known float process. Conventional titanium nitride filming methods involve the high temperature reaction of a source of titanium such as, for example, titanium tetrachloride, with ammonia. Such a method is disclosed in U.S. Pat. No. 4,535,000 to Gordon.
Fix, R. M. et al., "Titanium Nitride Thin Films: Properties and APCVD Synthesis Using Organometallic Precursors," Mat. Res. Soc. Symp. Proc., vol. 158 (1990) pp. 357-362 discloses a method for depositing thin titanium nitride films onto glass, by reacting together tetrakis(dialkylamido)titanium compounds and excess ammonia at about 100.degree. C. to about 400.degree. C. near the surface of the glass.
U.S. Pat. No. 3,784,402 to Reedy, Jr. discloses a method for producing metal carbonitrides. A gaseous stream containing hydrogen, a metal halide such as titanium tetrachloride, and an amine such as ethylene diamine, trimethylamine, or pyridine is reacted near the surface of a titanium metal or titanium nitride substrate. The amine decomposes during the reaction to yield nitrogen and carbon, which thereafter are used in the formation of the carbonitride. The patent also discloses the well-known reaction wherein titanium nitride is formed by the reaction between titanium tetrachloride, nitrogen, and hydrogen.
Finally, U.S. Pat. No. 4,162,338 to Schintlmeister discloses that a titanium carbonitride film may be formed by reacting together a titanium halide, a hydrocarbon gas, and an aliphatic or aromatic amine at a temperature from about 700.degree. C. to about 1,200.degree. C. The patent also discloses that titanium nitride may be formed by reacting together a titanium halide and nitrogen.
The prior art referred to herinabove has been collected and examined only in light of the present invention as a guide. It is not to be inferred that such diverse art would otherwise be assembled absent the motivation provided by the present invention, nor that the cited prior art when considered in combination suggests the present invention absent the teachings herein.